by BRE (01-Jan-1998)
Digest 427 brings up-to-date the information contained in Digests 274 and 275 which are now withdrawn.
The scarcity and cost of suitable land is leading to the development of sites where there are deep deposits of fill. Occasionally cases are reported where serious failures have occurred. These reports should not obscure the fact that many buildings have been successfully built on fill; they emphasise the importance understanding the behaviour of fills, identifying potential hazards and adopting measures that will ensure successful development of these sites.
This digest is divided into three separate publications:
Part 1 provides a general introduction, describes the causes of settlement of fill and gives guidance on the likely magnitude of settlement in different situations. A simple classification of fill materials is based on estimated fill movements.
Part 2 describes approaches to site investigation, techniques for improving the load-carrying characteristics of non-engineered fills, and aspects of foundation design for fills.
Part 3 deals with the specification and control of placement of engineered fills.
The three parts give guidance only of a general nature and it must be recognised that the services of civil, structural and geotechnical engineers will usually be needed. More detailed information concerning building on fill is given in Building on fill: geotechnical aspects (BR424).
This publication - Part 2 - recommends that construction on existing filled areas should be preceded by careful investigation of the site which should be both appropriate and adequate. The site investigation may indicate that ground treatment is required before construction to improve the load-carrying properties of the fill, reducing or forestalling the effects of the unexpected.